A revision surgery can be performed after an orthopedic implant has failed. The components of the implant may have worn out or broken, the patient body may have rejected the implant, or the bone and surrounding tissues may have become infected. Because the bones of the joint have already been altered due to the previous implant surgery, normal bone landmarks at the joint may no longer be present. In addition, conventional X-ray or Computed Tomography (CT) scanning can be highly affected by echoing resulting from metal implant parts; thus a clear scan of the bone area near the metal implant can be difficult or nearly impossible to obtain. A revision surgery can thus be challenging due to infection, patient discomfort, or difficulty in obtaining an accurate depiction of the bone near the joint line.
In a conventional revision surgery, in order to determine the final three dimensional positioning of an implant, an aperture can be drilled in the end of a femur for example for the placement of a femoral implant stem. A surgeon then needs to decide the “rotation” of the implant, in other words, twisting the implant or provisional about the stem and fixing a final rotational position. The surgeon must then decide how far in or out the implant should be placed in the stem hole. This positioning can determine the ultimate joint line of the implant.